Elastic scattering of o -Ps by H2 at low energies
Abstract
We investigate the low-energy scattering of orth-positronium by H2 from first principles of quantum mechanics using explicitly correlated Gaussians as basis functions. Using the confined variational method, we obtain highly accurate S-wave phase shifts and pick-off annihilation parameters for different incident momenta. With the least-squares fit of these data to the effective-range theory expansions, we determine the S-wave scattering length As = 2 . 09a0 and the zero-energy value of pick-off annihilation parameters 1Zeff = 0 . 186 . The present value of 1Zeff is in good agreement with the experimental values 0 . 194 (4) and 0 . 186 (1). In addition, the present value of S-wave scattering length 2 . 09a0 agrees well with the experimental value 2 . 1 (2) a0 estimated with the experimental momentum-transfer cross section.
- Publication:
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APS Division of Atomic, Molecular and Optical Physics Meeting Abstracts
- Pub Date:
- May 2018
- Bibcode:
- 2018APS..DMPM01035Z